Kelvin to Celsius Converter
Convert Kelvin to Celsius instantly. °C = K − 273.15. Formula, table and how hot a star's surface really is.
Written by Rahman · Last reviewed
Quick answer
To convert Kelvin to Celsius, subtract 273.15: °C = K − 273.15. So 300 K, often used as a rough "room temperature" figure in physics, is 26.85°C.
K to C conversion table
| K | C |
|---|---|
| 1 K | -272.15 C |
| 2 K | -271.15 C |
| 3 K | -270.15 C |
| 4 K | -269.15 C |
| 5 K | -268.15 C |
| 6 K | -267.15 C |
| 7 K | -266.15 C |
| 8 K | -265.15 C |
| 9 K | -264.15 C |
| 10 K | -263.15 C |
| 20 K | -253.15 C |
| 30 K | -243.15 C |
| 40 K | -233.15 C |
| 50 K | -223.15 C |
| 60 K | -213.15 C |
| 70 K | -203.15 C |
| 80 K | -193.15 C |
| 90 K | -183.15 C |
| 100 K | -173.15 C |
| 250 K | -23.15 C |
| 500 K | 226.85 C |
| 1000 K | 726.85 C |
How to convert K to C
Astronomy is where Kelvin shows up outside a physics classroom: the Sun's visible surface is measured at roughly 5,778 K, which converts to about 5,505°C, an almost meaningless distinction at that scale, since the 273-degree offset barely matters once temperatures run into the thousands. Kelvin is used here not for precision at this end but for consistency with the underlying physics, which is written in Kelvin throughout.
A photography and lighting use of Kelvin sits at the opposite, much cooler end: "colour temperature" for light bulbs and camera white balance is quoted in Kelvin (a "3000 K" bulb is warm/yellowish light, "6500 K" is cool/bluish daylight) even though nothing is literally that hot. The number describes the colour a theoretical object would glow at that temperature, borrowed from physics as a naming convention.